Optimization Of Preparation Process And Experimental Study On Strontium Chloride/Expanded Graphite Composites Adsorbents

As an energy-saving and environment-friendly refrigeration method,adsorption refrigeration has attracted extensive attention due to its outstanding advantages in the application of low-grade heat sources.In recent years,domestic and foreign scholars did a lot of research,but there still exist some problems to be solved,one of the most critical is the heat and mass transfer of adsorbent.In view of the heat and mass transfer problem of adsorbent,the paper add glucose in the strontium chloride/expanded graphite composite adsorbent,then use the vacuum atmosphere furnace fire to get strontium chloride/glucose/expanded graphite composite adsorbent.The paper test the factors such as firing time and ratio of samples on its adsorption performance,and explore the factors such as the pressing direction,the density of suppressing and firing time on influence the heat and mass transfer performance through the coefficient of thermal conductivity and permeability test system.The details are as follows:(1)To optimize the preparation technology of compound adsorbent in strontium chloride/expanded graphite composite adsorbent with glucose and through the vacuum with nitrogen as the protection atmosphere in furnace gas fired the carbide in full,and then through constructing the adsorption performance test of test bench test firing time and glucose content on the composite adsorbent adsorption performance and the effects of decay resistance,obtained the optimal ratio and optimal firing time.The results showed that expanded graphite and strontium chloride in composite adsorbent mass ratio of 1:2,strontium chloride and glucose,mole ratio of 1:1,protection gas for nitrogen fire 3h,the adsorption performance of compound adsorbent and decay resistance is better.(2)Test and analyze influence to the heat and mass transfer performance of direction of suppressing,pressing density and firing time through the thermal conductivity and permeability test system.The results showed that under the same pressed density,vertical direction of solidification heat and mass transfer performance of graphite and composite adsorbent are good in the horizontal direction,and under the same pressing direction,the solidification heat transfer performance of graphite and composite adsorbent with pressed density increases,and mass transfer performance decreases with pressed density increase,the firing time of composite adsorbent on its heat and mass transfer performance is very small.In practical application,the choice of pressing direction is perpendicular to the application direction,and the suppression density is 500kg/m3,which can achieve better heat transfer and mass transfer performance.(3)Combining BET and SEM test results and adsor:ption performance test results,we know that with the increase of the firing time,the glucose in the composite adsorbent is continuously carbonized and forming microporous structure.But when fully carbonized,the microporous structure is sintered,the surface area decreases and the adsorption performance becomes worse.